Dual cord interlock

ABSTRACT

A xerographic reproduction machine employing dual power input lines to divide the machine power load between two electrical circuits to prevent overload of either circuit.

United States Patent 1191 Crane May 7, 1974 DUAL CORD INTERLOCK 3,582,669 6/1971 Dempsey 307/18 Inventor: Arthur T. Crane, Penfield, N.Y.

[73] Assignee: Xerox Corporation, Stamford, Primary Examiner Robert Schaefr Conn- Assistant Examiner-M. Ginsburg [22] Filed: Dec. 11, 1972 [2]] Appl. No.: 314,219

' [57] ABSTRACT [52] US. Cl. 307/18, 355/3 R [51] Int. Cl. H0lh 47/00 v [58] Field of Search 317/31; 307/29, 18,92, A Xerographw reproduction machme employmg dual 307 43 75; 355/3 R 1 74 53 power input lines to divide the machine power load r between two electrical circuits to prevent overload of [56] References Cited elthel' clrcult- UNITED STATES PATENTS 3,620,615 l1/l971 Volkers 355/3 4 Claims, 1 Drawing Figure BACKGROUND OF THE INVENTION than would be possible by manually performing these operations. I

In an electrostatic copying machine of the type using a photoconductive layer for developing a latent electrostatic image of the document to be copied and thereafter developing and transferring the image toa copy sheet, various processing stations are utilized for uniformly charging, exposing and developing the photosensitive surface, transferring the developed image to a copy sheet, fusing the transferred image on the copy sheet, cleaning the photoreceptive surface, etc. Provision must also be made for the efficient and accurate movement of sheets of copy paper from the supply station to the transfer station of the machine. As the copy speeds increase, power requirements for each of the processing stations and the paper feeding and transporting mechanisms all increase accordingly. This is especially true at the fusing station of the machine wherein heat is applied to the powdered image on the copy sheet to fuse the powder to the paper. As the copy sheets move faster through the fuser, the heating capabilities of the fuser must be increased to provide'the required amount of heat to the copy paper and the powder in a much shorter time interval.

In many installations, the copy machine is located in an office building or similar environment constructed at a time when. office equipment power load was relatively low. Thus, many buildings do not have electrical circuits adequately sized to carry the power load for a high speed copier/reproduction machine having peripheral equipment associated therewith.

SUMMARY or THE INVENTION This invention relates to a xerographic reproduction machine employing a plurality of power lines adapted for connection to separate electrical circuits, each line having relay means therein operatively associated with one of the other lines to prevent current flow through any line unless all lines are connected to operative power circuits.

BRIEF DESCRIPTION OF THE DRAWINGS The drawing comprising a single FIGURE is a schematic sectional view of a reproduction machine showing the various processing stations therein and the power supply lines and interlocks associated therewith to provide power to the machine.

DESCRIPTION OF THE PREFERRED EMBODIMENT For a general understanding of an electrostatic processing system in which the invention may be incorporated, reference is had to the drawing in which various components of a system are schematically illustrated. As in most electrostatic systems such as a xerographic machine, a light image of the original to be reproduced is projected onto the sensitized surface of a xerographic plate to form an electrostatic latent image thereon. Thereafter, the latent image isdeveloped with an oppositely charged developing material comprising carrier beads and smaller powder particles triboelectrically adhering thereto to form a xerographic powder image corresponding to the latent image on the plate surface. The powder image is then electrostatically transferred to a support surface to which it may be fixed by a fusing device whereby the powder image is caused permanently to adhere to the support surface.

The electrostatically attractable developing material commonly used in electrostatic reproduction systems comprises a pigmented resinous powder hereinafter referred to as toner, and carrier of larger granular beads formed from a material removed in the triboelectric series from the toner so that a triboelectric charge is generated between the toner powder and the granular carrier. The carrier also provides mechanical control so that the toner can be readily handled and brought into contact with the exposed xerographic surface where the toner is attracted to the electrostatic latent image from the carrier to produce a visible powder image on the xerographic surface.

In the illustrated machine, an original D to be copied is placed upon a transparent support platen P, fixedly arranged in an illumination assembly generally indicated by the reference numeral 10. While upon the platen, an illumination system L comprising two or more lamps and reflectors is flash energized to direct light rays upon the informational areas on the original. In a high speed reproduction machine, the exposure time must be minimized. Therefore, high intensity lighting having a substantial power requirement must be utilized for proper exposure. The image rays are projected by means of an optical system 1 1 to an exposure station A for exposing the photosensitive surface of a moving xerographic plate in the form of a flexible photoconductive belt 12. In moving in the direction indicated by the arrow, prior to reaching the exposure station A, that portion of the belt being exposed would have been uniformly charged by a corona device 13 indicated at a belt run extending between belt supporting rollers 14 and 15, the latter being the drive roller for the belt. Due to high process speeds, the corona device must have a fairly large ion discharge rate and the belt drive motor must have adequate power for moving the I belt at the rate necessary for high speed copying. Thus,

there is an increased power requirement for both, the device 13 and the belt drive motor. The belt run between these rollers is encompassed entirely by the exposure station for minimizing the space required by the belt and its supporting rollers.

The exposure of the belt to the light image discharges the photoconductive layer in the areas struck by light whereby there remains on the belt a latent electrostatic image in image configuration corresponding to the light image projected from the original document.

As the belt surface continues its movement, the electrostatic image passes around the roller 16 to a developer station B located at a third run of the belt in which there is positioned developing apparatus generally indicated by the reference numeral 17. The developer apparatus 17 comprises a plurality of brushes adapted for rotation by a suitable motor 18 to carry developer along the adjacent surface of the upwardly moving inclined photoconductive belt 12 to provide development of the electrostatic image.

The developed electrostatic image is transported by the belt 12 to a transfer station C'located at a point of tangency on the belt around the drive roller 15 whereat a sheet of copy paper is moved at a speed in synchronism with the moving belt in order to accomplish transfer of a properly registered developed image. A transfer roller 19 is provided at transfer station C for contacting the upper surface of the copy paper to assure good contact between the copy paper and the belt 12 during transfer of the toner image from the belt to the paper. An electricalbias may be provided on roller 19 to attract the toner from belt 12 to the copy paper.

There is also provided a copy sheet supplying apparatus comprising a main paper feed supply 20 and an auxiliary paper feed supply 21. The sheet supplying apparatus is adapted to separate sheets from their respective supply stacks'and to transport the sheets to a sheet registration station and eventually into contact with the developed image on the belt as the same is carried around the drive roller 15. Suitable control means 29 are operatively associated with each of the paper supply mechanisms 20, 21 and the flash illumination device L for producing an electrostatic latent image on the belt 12 to present a developed image at the'transfer station C intimed sequence with the arrival of a sheet of paper, and is coordinated with the activation of other processing and control devices at the precise time that these elements are to function for their intended purpose.

After the developed image is transferred to a sheet of paper, it is stripped from the belt 12 and conveyed by conveying system 23 into a fuser apparatus generally indicated by reference numeral 24-wherein the developedand transferred xerographic powder image on the sheet material is affixed thereto. At the high process speeds encountered, fuser heating capacity must be fairly high in view of the fact that the copy paper passes so rapidly therethrough. After fusing, the finished copy is discharged from the apparatus by a conveyor 25 at a suitable point for collection externally; of the apparatus. The toner particles remaining as residue on the developed image and those particles not otherwise transferred are carried by the belt 12 to a cleaning apparatus 26 positioned on the run of the belt between the rollers 14 and 15 adjacent the charging device 13. The cleaning apparatus comprises a discharge device 27 for neutralizing charges remaining on the belt and a rotating brush 28 which operates in conjunction with a vacuum system to remove the residual toner particles from the belt.

It can be seen from the foregoing that increased copy requirements of todays business firms have resulted in high speed copiers having fairly large power requirements for energizing the various machine processing stations and peripheral equipment such as document feeders and collating equipment. Further, as copy speeds increase, fairly complex electrical control systems are requiredto program the machine, activate the various processing stations at the required time, and monitor the entire copying cycle to minimize the possibility of a malfunction therein.

In todays offices, it is common to find power supplies such as 208-230 volt 30 amp circuits for operating small copy machines or similar equipment. It is also common to find l 10-120 volt, 15 amp circuits for operating normal business machines such as electric typewriters, calculators, etc. In order to utilize these power supply circuits for a machine requiring over 30 amps, dual lead-in lines 40 and 42 are provided for connecting the xerographic reproduction machine to more than one power supply in the office or area wherein the machine is located. Preferably, line 40 would be adapted for connection to a 1 10-120 volt circuit while line 42 would be adapted for connection to a 208-230 volt circuit. Each line would be adapted to provide current through control means 29 to various elements of the machine. For example, the 1 10-120 volt circuit may be employed for energizing the machine vacuum system, the developer motor, cooling blower motors,

the paper feeders and transports, while the 208-230 volt circuit may be utilized for powering the main drive motor, flash lamps, fuser, etc.

Since the machine could be damaged by an attempt to operate the machine with one of the lines disconnected or connected to an inoperative circuit, an interlock is provided to prevent current flow to the machine through either line unless both lines are connected to operative circuits. The interlock comprises a first relay 44 having contacts 46 in line 40 anda second relay 48 having contacts 50 in line 42. The relay 44 is provided with a coil 45 connected to line 42 to close the contacts 46 in line 40. Conversely, the second relay 48 is provided with a coil 49 connected to line 40 to close the contacts 50 in line 42.

Thus, ifline 42 is disconnected or a fuse in the circuit is blown, coil 45 will be de-energized, allowing contacts 46 to open and prevent current from flowing through line 40 to the reproduction machine. If line 40 is connected, since there is no current flow through line 42, the fact that coil 49 would maintain contacts 50closed would be of no consequence and all power would be cut off to the machine. The same would be true if current were suppliedto line 42 and line 40 'were disconnected or'connected to a dead circuit. With current supplied to both lines 40 and 42, both coils 45 and 49 would be energized to hold contacts 46 and 50 closed to provide current to the machine.

Thus, the reproduction machine may be adapted for connection to more than one circuit and by means of the interlock provided by the relays 44 and 48, the danger of energizing a portion of the machine through one line while another portion is disconnected is obviated.

While I have described a preferred embodiment of my invention it is to be understood that the invention I is not limited thereto but may be otherwise embodied within the scope of the following claims.

What is claimed is:

l. A reproduction machine for producing copies of an original including:

a plurality of electrically actuated devices for feeding copy paper through the machine and producing copies of the original thereon;

a first power input line electrically connected to a first group of said electrically actuated devices, said first power line being adapted for connection to a suitable source of electricity to supply power for energizing said first group of devices;

a second power input line electrically connected to a second group of said electrically actuated devices, said second power line being adapted for connection to a suitable source of electricity to supply power for energizing said second group of devices;

first circuit interrupting means associated with said first power input line and associated with means to prevent current flow through said first power input line in the absence of power in said second power input line; and,

second circuit interrupting means disposed in said second power input line and associated with means to prevent current flow through said second power inputline in the absence of power in said first power input line to prevent power input to the machine unless power is available at both said first power input line and said second power input line.

2. A reproduction machine according to claim 1 wherein said first circuit interrupting means and said associated means comprises a first relay having a set of contacts and a coil, said contacts being disposed in said first power line, said coil being connected to said second power input line; connection of said second power input line to a power source energizing said coil for closing said contact set and;

said second circuit interrupting means and said associated means comprises a second relay having a second set of contacts and a second coil, said second set of contacts being disposed in said second power input line, said second coil being connected to said first power input line, connection of said first power input line to a power source energizing said second coil for closing said second contact set, said relays preventing power input through either of said power input lines unless both lines are supplied with electrical power.

3. An electrostatic printing apparatus for reproducing copies of an original including:

a plurality of electrostatic processing stations for producing toner images of the original for transfer to suitable copy paper;

a first power input line electrically connected to a first group of said electrostatic processing stations,

'6 said first power line being adapted for connection to a suitable source of electricity to supply power for energizing said first group of processing stations;

a second power input line electrically connected to a second group of said electrostatic processing stations, said second power line being adapted for connection to a suitable source of electricity to supply power for energizing said second group of processing stations;

first circuit interrupting means associated with said first power input line and associated with means to prevent current flow through said first power input line in the absence of power in said second power input line; and,

second circuit interrupting means disposed in said second power input line and associated with means to prevent current flow through said second power input line in the absence of power in said first power input line to prevent power input to the apparatus unless power is available at both said first power input line and said second power input line.

4. An electrostatic printing apparatus according to claim 3 wherein said first circuit interrupting means and said associated means comprises a first relay having a set of contacts and a coil, said contacts being disposed in said first power input line, said coil being connected to said second power input line; connection of said second power input line to a power source energizwith electrical power. 

1. A reproduction machine for producing copies of an original including: a plurality of electrically actuated devices for feeding copy paper through the machine and producing copies of the original thereon; a first power input line electrically connected to a first group of said electrically actuated devices, said first power line being adapted for connection to a suitable source of electricity to supply power for energizing said first group of devices; a second power input line electrically connected to a second group of said electrically actuated devices, said second power line being adapted for connection to a suitable source of electricity to supply power for energizing said second group of devices; first circuit interrupting means associated with said first power input line and associated with means to prevent current flow through said first power input line in the absence of power in said second power input line; and, second circuit interrupting means disposed in said second power input line and associated with means to prevent current flow through said second power input line in the absence of power in said first power input line to prevent power input to the machine unless power is available at both said first power input line and said second power input line.
 2. A reproduction machine according to claim 1 wherein said first circuit interrupting means and said associated means comprises a first relay having a set of contacts and a coil, said contacts being disposed in said first power line, said coil being connected to said second power input line; connection of said second power input line to a power source energizing said coil for closing said contact set and; said second circuit interrupting means and said associated means comprises a second relay having a second set of contacts and a second coil, said second set of contacts being disposed in said second power input line, said second coil being connected to said first power input line, connection of said first power input line to a power source energizing said second coil for closing said second contact set, said relays preventing power input through either of said power input lines unless both lines are supplied with electrical power.
 3. An electrostatic printing apparatus for reproducing copies of an original including: a plurality of electrostatic processing stations for producing toner images of the original for transfer to suitable copy paper; a first power input line electrically connected to a first group of said electrostatic processing stations, said first power line being adapted for connection to a suitable source of electricity to supply power for energizing said first group of processing stations; a second power input line electrically connected to a second group of said electrostatic processing stations, said second power line being adapted for connection to a suitable source of electricity to supply power for energizing said second group of processing stations; first circuit interrupting means associated with said first power input line and associated with means to prevent current flow through said first power input line in the absence of power in said second power input line; and, second circuit interrupting means disposed in said second power input line and associated with means to prevent current flow through said second power input line in the absence of power in said first power input line to prevent power input to the apparatus unless power is available at both said first power input line and said second power input line.
 4. An electrostatic printing apparatus according to claim 3 wherein said first circuit interrupting means and said associated means comprises a first relay having a set of contacts and a coil, said contacts being disposed in said first power input line, said coil being connected to said second power input line; connection of said second power input line to a power source energizing said coil for closing said contact set; and, said second circuit interrupting means and said associated means comprises second relay having a second set of contacts and a second coil, said second set of contacts being disposed in said second power input line, said second coil being connected to a said first power input line, connection of said first power input line to a power source energizing said second coil for closing said second contact set, said relays preventing power input through either of said power input lines unless both lines are supplied with electrical power. 